punchingclothes-deactivated2012 asked: I have a question!

Say for example I've written a sentence: I went to the store today (which actually happened to be open for business!)

Would I still have put a full stop at the end of that sentence outside the brackets even though I've ended it with an exclamation mark on the inside?

Yes, you would put a period on the outside of the parentheses. Even if you use punctuation right before the brackets, one still needs to go outside if it is the end of the sentence.